THE CORBIN TECHNICAL BULLETINS
Volume 1
THE CORBIN TECHNICAL BULLETINS
Volume 1
Corbin Manufacturing and Supply, Inc.
THE CORBIN TECHNICAL BULLETINS
Volume 1
Corbin Manufacturing and Supply, Inc.
CONTENTS
Introduction Definitions Definiti ons
Page Page 1
What is Swaging?
Page 17 TECHNICAL BULLE TINS
1-3-76
Copyright © 1977 David R.
Corbin
Published in the United States of America. All rights reserved. No part of this book may be reproduced in any form without the permission of Corbin Manufacturing & Supply, Inc. Printed in the
United States of America by Wegferd Publications,
North
Bend,
Oregon.
Special Note Not e on Die Adjustment & Excess Pressure
Page 29
2-1-76 Rimf
Page31
ire
Jack et
Characteristics
3-4-76 Hollow Point and Cup Base Bullets
Page35
4-22-76 Bullet Bull et Jacket Jack et Design gn & Selection
Page38
5-25-76 Illustrations Illustrati ons of Bullet Length L ength & Weight in Handgun Handgun Jacket s
Page41
6-10-76 Comparison of Casting & Swaging
Page 44
7-10-76 Core Swage Die Adjustmen Adj ustmentt & Use
Page 49
8-12-76 Redrawing Redrawing Bullet Jackets ; Determination of Internal Die Pressures Pressures
Page Page 51
9-15-76 Factors Determining the Diameter of Swaged Bull ets
Page 54
10-15-76 Removal of Stuck Bullets in Point Forming Dies
Page56
11-1-76 Dealer's Guide to Customer Questions about Bullet Bul let Swaging
Page 58
12-1-76 Bullet Designs for Deep Penetration: Multi-Jacket Multi -Jacket Swaging
Page64
INTRODUCTION
This volume of the Corbin Technical Bulletins covers the period from January of 1976 to December of 1976. It is not the definitive work on the subject of bullet swaging, nor does it come close to covering all the aspects and technicalities of this fascinating field. Rather, it is a collection of responses to customer questions, dealer inquiries, and problems that have arisen in the course of the year for which concise answers covering specific points were needed. Each subject is answered from the knowledge directly acquired by per formi ng lab and field tests. Changes in technology and manufacturing methods can make some of these answers obsolete in a few instances, but in general they are broad enough to serve as a guide for the immediate use of custom bullet makers, home enthusiasts and experimenters, and the dealers who need a source of swaging information. Bullet swaging is experiencing a rebirth today among handloaders , not just because of the high precision it affords to the benchrest rifle shooter, but because of the broad versatility it brings to all the shooting sports. The main obstacle to wider enjoyment is simply lack of information. Hopefully, the Corbin Technical Bulletins will help fill the immediate voids while better structured books are being prepared. David R. Corbin
A rim fire jacket made fr om a .22 Long Rifle case is formed into a .243 bullet in this illustration. The jacket pre-form has a flared mouth, this caused by the two-diameter jacket drawing punch. When the lead core i s seated, the larger diameter point forming punch is normally used with the lead seated so it is longer than the jacket. Then the flared jacket mouth creates a pressure seal in the core seating die, and the lead pressure brings the jacket up to fill the bore. A conventional weight .243 caliber bullet uses at least a .750" jacket length, while the .22 Long Rifle makes about a .705" jacket. Thus, the point of a rimfire jacket .243 is considerably formed by lead alone. Velocity must be held down to moderate levels so that the lead tip does not flow back upon firing. When this, is done properly the
DEFINITIONS
BULL ET SWAGI NG . . . A method of producing bullets by forming a soft metal under high pressure, within a highly-finished steel die. The home swager uses a hand press, which can be the ordinary reloading press, to apply pressure to precision-fitted punches which then transfer the pressure to the lead and jacket (if used). The shape of the bullet results from the forcing of the metal against the die walls and the punch ends. BULLET JA CK ET . . . A deep-drawn cup of copper and zinc (other
In the middle row are designs for expansion at low speed. These are typically very large cup points with thin walls. They often are limited in range, with poor ballistic co-efficients, as they are very light for their length and have a poor ballistic shape for any long range work. Their purpose is outstanding expansion at low speeds, such as use in the .44 Special or .38 Special in light frame revolvers. Many autoloaders will not feed these bullets. They are a good answer to home defense loads since the y will not penetrate walls or doors as readily as standard bullets of the same velocity. In police use they are good man-stoppers but lack penetrati on against cars, glass, doors, or sometimes very heavy clothing. At higher speeds they are very damaging at combat ran ges, and it may be necessary to use the two-die swage set to produce bullets with t he ogive going into the jacket (to cut down leading or eliminate it entirely). Then the cavity becomes pear-shaped within the bullet.
materials are rarely used) which is placed over the lead core before swaging. The jacket forms the outer skin of the bullet, protecting the lead core from barrel friction, powder gasses, and air friction. The jacket is sometimes called the cup, a term more often applied to short handgun jackets and jackets which are only partially drawn to full length. Jackets may vary from as little as 0.010" thick to 0.050" or more, depending on their caliber and purpose. The usual alloy for jacket "copper" is actually a low-zinc brass of from 5% to as much as 10% zinc and the rest copper. The term gilding metal is frequently used to describe this alloy. OGIVE . . . The portion of the bullet which curves inward from the body, at the start of the nose section. A bullet may be made so that the ogive begins smoothly from a tangent to the cylinder portion, or it may start with an angle as in the spire point or conical nose bullets. The term ogive is sometimes used interchangably with
In t he front row are some designs for high velocity use, offering delayed expansion. The rifle style with the jacket brought over the l ead in a windshield is really two bullet forms in one. . . the core is a wadcutter with high shock effect and the jacket is a windshield offering good ballistic f orm. If driven high enough in velocity so that the jacket folds or ruptures upon striking the t arget, the ballistic form is instantly changed to a high-expansion style (brought rapidly to a stop, which creates greater force to expand the bullet than if the jacket and core expanded more slowly together). The inside seated core with a round shape but left so that the jacket is open offers a more rapid expansion but poor trajectory. The cup point which is made so that the core is entirely within the jacket gives better trajectory but does not reduce expansi on at higher speeds. The cup point wadcutter with both a half and a three-quarter jacket, one on either end, offers protection from leading, high
TI P . . . The very last part of the bullet's nose. This term should only be used to describe the form which the very end of the ogive takes, not to describe the entire ogive. For example an open tip bullet has jacket extending past the lead, a lead tip bullet has lead extending past the jacket, a flat tip bullet has the lead either flush with or extending past the jacket with a broad flat form,
Many styles of expanding bullets, made with the use of various size hollow point punches or other special punches. In the back row are the more conventional hollow points. These feature exposed lead tips with the lead core ho/ding a relatively small diameter, deep cavity. They feed in most autoloaders, and offer a delayed expansion at moderate speed. At low velocity they may not perform well, and at very high velocity they may shatter without penetration.
nose.
POINT .. . The words tip and point are used to mean the same thing in most conversation. A hollow point bullet should not be used to mean an open tip, however, because there is a need for a different term to describe these two forms. The hollow point is a bullet with lead either flush or extending past the jacket, and with a cavity pressed or otherwise formed into the lead. The open tip is simply a bullet which has the lead core seated below the end of the jacket, so that when the ogive is formed, a "windshield" is formed of the jacket alone, similar to the construction of some artillery projectiles and bombs. The open tip bullet is often used for match shooting while the hollow point is more often used for defense and game. BASE . . . The base of the bullet is the end that comes out the gun barrel last.
A closer examination of three forms of cup point bullets. The cup formed of jacket only with a seating punch turned down to fit inside the jacket, gives complete freedom from leading wit h delayed expansion. The shallow cup point offers great shock on impact cuts a full-diameter hole at any velocity, and is also good from a leading standpoint though it does tend toward more leading at high speeds. The normal 3/4 jacket becomes a half jacket in the huge cup point .44 bullet, offering sacrifice of just about every desirable characteristic in favor of low speed expansion and shock. This is a .44 Special defense bullet made so it is less likely to penetrate walls or doors, but very likely to stop an intruder in one shot. It will lead the bore, have a rainbow trajectory, and fail to penetrate deeply enough for use on game This is an extreme example of designing for a single purpose. The bullet will a/most expand upon hearing the words commence fire" as a trade-off for all other features
BOA TT AIL .. An angled portion of the bullet that reduces the diameter of the base from that of the main body. Boattail bullets normally require several extra steps in production, including pre-forming of the jacket and pre-forming of the core to match. They result in a longer bullet for a given weight, giving slightly improved ballistic coefficient, but are more difficult to make properly with home swaging equipment and do tend toward increased gas and powder particle erosion since they do not make as good a seal of the bore under pressure. At all speeds, but especially noticable at low velocities, the drag of air friction at the bullet base is reduced with a boattail bullet design. REBATE D BOA TTA II A reduction in the diameter of the bullet at the base which is achieved by a sharp step rather than a gentle slope, quite often combined with a gentle angled portion after the step. This kind of base can be created by a cavity machined into the core seating punch and retained by similar cavities on all following punches in producing home swaged bullets. The end of the punch create the rebated step, while the walls of the cavity in the punch form the gentle boattail section. Remarkable accuracy has been achieved with this type of base section, though punch life is generally not as good as with a standard flat or cup base punch.
Accuracy can often be improved by using a cup base design i n small autoloaders. The left target was shot with a fl at base factory bullet. The right one was fir ed with a cup base swaged bullet at the same velocity. The same gun was used for both. The improvement in accuracy is evident. The cause is primari ly the longer bearing surface that is created when a bullet is made with a step shoulder and cup base in the same weight as a standard ogive flat base bullet.
CA NN ELURE . . . An indentation rolled into the bullet or its jacket after forming, or cast into a cast bullet by raised rings in the mould, which is used for lubricant on lead bullets, crimping area for the mouth of the cartridge case, or to help control expansion of the bullet on impact. A cannelure can also be used on a cartridge case, to act as identification of a load or to stop the bullet from receding into the case during feeding, as with the .45 ACP round. The cannelure is generally produced by using a hardened steel roller against the side of the bullet while the bullet is turned in a machine for the purpose. Cannelures are more often found on pistol cases and bullets, and on hunting bullets, than match bullets. CORE SWAGE DI E . . . A die used to pre-form the lead core and adjust its weight to a consistent value before it is put into the jacket. Core swages have one or more tiny bleed holes drilled to the main cavity from the sides of the die. The press and die are adjusted so that a fixed distance will remain between the top punch and the bottom punch whenever the ram is moved forward. This distance is the fixed length of the core after it is swaged. It is necessary for the press to fit a positive stop or to pass exactly over center each time in order to maintain this fixed distance. Cores are cut or cast of lead, and made slightly longer than this distance so that each core will more than fill the volume of the die cavity. Then each core will be forced to bleed off some amount of surplus lead through the tiny bleed holes. The variations in core weight are removed when the core is ejected, since all the variation is bled through the tiny holes and is sheared off by the top punch. The core swage is an accessory die used to gain greater accuracy. CORE SEATING DIE . . . A straight-walled die fitted with top and bottom punches, which is used to seat the lead core into the jacket. A variation of the core seating die is the straight-walled pistol bullet swage die. This die is exactly like the core seating die except that it is generally made at the finished b u l l e t diameter, and has the nose shape of the finished bullet cut and polished (reamed and lapped) into the bottom punch. This forms a cavity into which the lead core will be extruded under high pressure during the swaging process. Such a die makes a finished bullet on one stroke of the press. The jacket cannot be brought
The skin of the bullet. . . the j acket. . . comes in many lengths, diameters, and even qualities of draw. Shown are jackets from . 17 to .45 Cat. The long rifle jacket is actually a blank blasting cap, showing the similarit y to a bullet jacket. Many items are drawn in the same manner as jackets, including flashlight cases, some electronic component bodies, and similar deep drawn parts. The material starts as a strip of gilding metal in a large roll, in most cases, and is drawn in many steps after being blanked into a small thick disc. Jackets can be trimmed by rotary t rimmer or by die trim. One form of die trim is the pinch tri mmer, which leaves a thin edge in most cases but is usually very even and has no curl or burr. Jacket quality is determined in part by the variation in thickness of the walls from one side to the other, and superficiall y by the quality of trim. Half jackets are very short, and generally t ake fewer draws, so are cheaper even though they may contain the same amount of metal as the longer 3/4-length or f ull jacket. A .45 Cali ber half jacket is shown, and a rough-trimmed .30 caliber half jacket. The actual length depends on t he brand and caliber, but most half-jacket lengths are around a quarter inch long, with three-quarter length jackets going about a half inch long. Most of the half and three-quarter jackets are used with cores longer, when seated, than the jacket and thus a bore-size punch is used (same diameter as the die cavity). In general, the rifle and long jackets use cores seated within the jacket, so that punches are used which can slip inside the jacket rather than filling the die. With transition lengths such as the full jacket handgun styles, both kinds of punches may be desirable.
of the punch would strike the end of the jacket. POINT F ORMING DI E . . . The die which brings the jacket and lead into the ogive shape. This die is a complex item with the actual bullet shape lapped into the die itself. At the very tip of the cavity is a small but extremely tough ejection pin punch which presses on the tip of the bullet to eject it. This punch takes no part in the forming of the bullet during swaging, unlike the top punch in other dies. The term "point" is generally used here to mean-the nose or ogive, which is a deviation from normal definition and can be confusing to the beginner. A better term is "ogive-wall" die, which describes the form of the die walls, as opposed to the "straight-wall" die used for core seating. The ogive-wall die or point forming die is never used with a jacket which has a loose core, but must be used to form the nose only on slugs which have the lead core firmly seated into the jacket, and the jacket expanded to nearly finished size. TWO-DIE SET . . . Rifle bullets and some handgun bullets with the jacket brought into the ogive are formed in two steps using both a core seater (straight-wall) and a point former (ogive wall) die. The set of two dies are ordered and used together, since their diameters must be matched correctly. The core seater must produce a slug with a slightly smaller diameter than the bore of the point former. TH RE E-D IE S ET . . . Match grade rifle bullets are usually made in a three die set which consists of the point forming die, core seating die, and the core swage die. The diameter of the core from the core swage die must be such that it is a slip fit into the jacket, which is then a slip fit into the core seating die. Punches for the core seating die (also called the "core seater") are made to fit the inside of the particular jacket used, at the point where the lead core will finally be swaged. Since most jackets taper internally the core seating punch can only be used on a narrow range of jackets and core weights, but the punches are inexpensive, making it possible to match any jacket and bullet weight to a correct diameter punch. CORE . . . The lead slug that is put into the jacket, or is swaged into an all-lead bullet, is called the core. It forms the bulk of the bullet weight, and is cut from rolls or sticks of lead wire that are available from die manufacturers in the proper diameters for a given caliber. The lead wire can be considerably undersized and still make a good
A .44 Magnum 3/4-length jacket redrawn to a 9.3mm rifle jacket in a simple home die set, illustrating the problem with using too short a core or t oo long a jacket with the handgun-style nose forming punch. If the lead is short enough so that it will not completely fill the nose punch cavity, then the punch edges will come down against the jacket during forming and fold the jacket. This is why a bullet with rifle-type ogive, formed mostly from the jacket, requires t wo dies. One is used just to seat the core inside the jacket, and the other has the shape of the bullet lapped into i ts walls, permitting the smooth forming of the nose in the jacket itself.
core. It will be swaged up to fit the inside of the jacket or core swage die. Oversized lead cannot be used for cores. Cores can also be cast from soft lead. Hard alloys must be avoided as they do not flow easily under the pressure of swaging used in home equipment. CUP B A S E . . . A cavity of nearly any size can be formed into the base of a bullet during swaging simply by using a top punch with a dome formed on it. The cup base is a depression in the base of the bullet, often used to gain better gas sealing from expansion of the base during firing. Other uses include making a lighter weight bullet with the same bearing surface, such as those used to gain velocity from short .25 and .32 ACP loads. The cup base must be held within certain constraints of design to avoid blow-out of the core and damage in revolver forcing cones from excessive expansion. A cup base of very slight depression is sometimes used on match bullets to create a center-first pressure that insures a more evenly formed base within the core of the bullet. Die sets can easily be changed at will from cup to flat base by changing the punches. ZINC B A S E W A S H E R ... A form of swaged bullet with a washer of zinc fastened to the base is sometimes used for higher velocity handgun bullets shot unlubed, and without a jacket. A regular die set makes these bullets in a single step, by using a punch with a "rivet" head depression in the center. The lead slug will extrude through the hole in the washer, and fill the "rivet" head depression, making a perfectly secured zinc washer on the base in one step, while the nose is formed in the other punch, simultaneously. UNLUBED . . . Not lubricated, a slang expression used to save typing six letters. BOTTOM PUNCH . . . The punch which is separate from the die and die body or adapter. In a reloading press, the bottom punch slips into the slotted ram, or in some systems fits a special swaging ram with threaded top. In a special press such as the Mity Mite, the term means the punch that is held in the special punch holder, in the head of the press, while the die fits the ram. TOP PUNCH . . . The punch that stays partly inside the die during all the swaging operations. In a reloading press, the top punch is held inside an adapter body which also holds the swage die itself, and is not visible. In a special
The .25 ACP shown with a greatly improved swaged bullet and the standard cast bullet. Three lengths of swaged bullets are shown. They are all functional, but the middle length gives best over-all performance. Bullet performance is related to its bearing surface to align in the bore during firing, its weight in relation to the power (pressure and recoil to operate the gun), and the nose form. Hollow points do little to improve performance while the small shoulder does greatl y increase the amount of shock power compared to a standard round nose. A .243 caliber gas check is used, not a .25 caliber (the .25 ACP is .250 while the .25 rifl e is .257, too large). The gas check expands t o proper diameter under swaging pressure.
the ram of the press and is put into the ram before the die is screwed into the ram threads. Either the top or bottom punch may perform functions of base or nose forming, depending on how the jacket and core are put into the die, and upon how the cavities are machined into the punches for handgun bullet forming. EJECT ION RAM . . . A steel rod with a head fastened to it, used to knock the top punch down and eject the formed slug or bullet. One ram will generally work with several dies in the standard reloading press type of arrangement. This item is not required with automatic ejecting presses such as the Mity Mite, since the top punch is automatically pressed forward on the backstroke of the press. PO WE R E J E C T O R . . . A mechanical devise used to facilitate ejection of slugs or finished bullets from swage dies. It multiplies the operator's effort through a powerful system of levers so that pressing a handle ejects the bullet from a die in a regular reloading press. Alternatives include ejection frames, fastened to the press ram and reaching over the top of the die, or the standard plastic mallet and ejection ram. The power ejector is an optional accessory item. CA LIBER . . . The caliber of a bullet is the nominal, commonly used designation for a given caliber of bore. It is not precise, and is sometimes very far from the actual diameter of the bullet. For example, a .30 caliber rifle usually has a .300" bore but with two opposite grooves of rifling each of 0.004" depth; a nominal caliber for the bullet would be 0.308". In this case, the caliber of the bullet is very nearly the same as the bore plus rifling depth of the gun. The bullet diameter might be 0.3077" to 0.3085" and still be very close to commercial bullet sizes, close enough to call a .308" caliber. But in the .44 Magnum, a bullet of 0.427 to 0.430 is used, depending on the gun. The bore may well be 0.420" with 0.004" rifling depth in some guns, so the .44 caliber bullet is not actually 0.440" or anywhere close to this diameter. Similar cases exist with the .380 caliber pistol (0.355" bullets) and many other calibers. In general, the diameter of the bullet must be no greater than the bore diameter plus twice the depth of rifling.
RiMF IRE J ACK E TS . . . This term refers to the use of fired, cleaned, and drawn .22 caliber empty cases for the jackets of .224 and 6mm bullets. Equipment is available to make jackets from fired .22 cases. These jackets can be extremely accurate under proper techniques of forming and loading, but are thinner than commercial jackets and cannot be driven as fast. They make excellent varmint bullets even at lower velocities because of their thinness and ease of expansion. HA LF -J AC KET . . . This is the term for a short jacket used on handgun bullets. The half jacket protects the base of the bullet from hot gasses but does not protect the bore from leading at moderately high velocities. Problems of the half-jacket stem from excessive speed, and lead to the development of the three-quarter jacket. In general, a half-jacket ranges from about 0.2" to 0.35" in height in any of the handgun calibers. They are not normally used for rifle bullets. TH RE E- QU AR TE R J AC KE T .. . A jacket which covers all or nearly all of the straight body portion of a bullet is a 3/4-jacket. This jacket can range from about 0.40" to 0.55" depending on the caliber. It does not cover any appr eciable amount of the ogive, and in the semi-wadcutter styles does not extend beyond the cylindrical part of the bullet into the nose portion. Velocities can be extended upward of 1,800 fps with the three-quarter jacket style bullet. Some light rifle bullets use this bullet style.
Some of the many shapes of noses that can be made in a single die set. Round conical Keith, button, and wadcutter types are all easily formed in this die set, but the small shoulder is necessary unless two dies are used. This shoulder is formed by the edge of the nose forming punch. The jacket cannot be made to flow around the edge of the punch. A lapped die is requi red, formed in the shape of the nose, to form bullets with the Jacket brought around the ogive. Any of these bullets can be ref ormed to any desired amount in such a die, givi ng a vast number of final shapes.
F UL L-J ACK ET . . . A military rifle bullet with the nose closed, and the base open, is a full jacket bullet. The term is sometimes used to cover the new, longer styles of handgun bullet jackets, but these should not be used for an inverted swaging of true full jacket bullets. The so-called full jacket for handgun calibers is upward of 0.5" in nearly all the handgun calibers and is in truth nothing but a short version of a rifle jacket, suited to the making of rifle-style bullets in handguns. The open point expanding bullets made popular by SuperVel use a jacket which covers nearly all the ogive, with only a portion of exposed lead, and a large hollow point. Almost unknown is the fact that a "windshield" style of open tip bullet can also be made in this manner, by using a short, small diameter seating punch to seat the handgun core into the "full" jacket just as if it were a rifle jacket. The
handgun "ogive" die will then form the jacket into an effective ballistic shape, while leaving the core primarily a wadcutter. Upon impact at high enough velocity, the jacket col lapses and the; core strikes with a devastating effect in softer target materials. At lower velocities this bullet may penetrate deeply without expansion, but generally is stopped by more solid materials and expands, making it a reasonable design for defense bullets used in areas where penetration of walls, etc., would be dangerous. CA LIBE RS OF RA DI US . . . A term refering to the measurement of spitzer type bullet noses in determining the form. A six caliber ogive refers to the form given to the bullet when a radius swung tangent to the bullet body is six times as long as the caliber. A .224 caliber bullet with a 6-caliber ogive can be drawn by marking a point exactly 1.344 inches away from the opposite wall of the bullet, and perpendicular to it, then swinging an arc beginning with the wall of the bullet and using this point as the center. The difference in form becomes less and less as the caliber designation increases. There is very little difference between a 10 caliber ogive and a 15 caliber ogive, but between a 1 and 2 caliber ogive a radical change is visible.
The core swage die made to fit a regul ar reloading press. The die is split to illustrate the bleed holes, made at the proper angle so that the lead will extrude out the front. The die holder is rel ieved at the mouth and is sl ightly larger internall y than regular die holders. The top rod is the length of the cavity i n the die plus a small amount for alignment. The head length adjusts the amount of protrusion into the die cavity. This can be changed to allow different ranges of core weights but one standard punch normally covers all the common weights f or a given caliber. The punch cannot protrude far enough to cover the bleed holes. Tremendous pressure is sustained by this small die, which must be operated properly in or der
WHAT IS SWAGING? Dave Corbin
A complete system for core swaging, just as it might appear within the ram and head of a Mity-Mite press or one of the converted reloading presses using speci al threaded rams. This one is an early model from SAS Dies. Note the lead extruding from the die bleed holes. In this system the die fits the press ram and the punch fit s a holder that looks much like a normal swage die. A simil ar system is now used on all the Mity Mite presses, with the addition of a perfected "floating alignment" punch holder.
Bullet Swaging is forming a bullet by using pressure . . . very high pressure, generated within the confines of a super-tough tool steel die between two close-fitting punches, or between one punch and the semi-blind end of a die. Swaging is cold-flowing metal, just as if it were a fluid. In fact, for most purposes, we might think of the swaging system as if it operated with a very viscous hydraulic fluid: a very lossy, or high friction, liquid. Of course, bullets can be cast of liquid metal by raising the temperature to the melting point of the metal, which is usually lead or a lead-tin-antimony alloy. This is one of the cheapest ways to make bullets... if a person only wants to make one or two basic sytles and weights in a given caliber. There are three problems with casting that make it less than ideal: (1) the bullets produced have a rather narrow performance range between the limits of barrel leading and lack of expansion, in an even more narrow velocity range, (2) each bullet weight and shape requires a complete new mould investment, with the design capability being limited to that of the mould-maker, and (3) there is a lot of waiting and handling involved in producing a cast bullet ready to shoot, including other investments such as lubricator/sizer, dies for the machine, extra handling, lead pot, and time waiting for lead to melt, clean-up time, and general tediousness of the whole procedure. This is not to condemn cast bullets, since for the shooter who is going to fire target revolver or automatic matches using one load, one bullet style, one weight, for years on end, there is nothing any cheaper or better. And for the hand loader who is quite satisfied with a design and performance level limited to a narrow range in rifle or handgun, a cast bullet that suits his needs is all that should ever be considered. There are a good many factory jacketed bullets available in most calibers to give the bullet caster an alternative for handloading, without necessarily turning to swaging equipment. But for the shooter who has advanced beyond tinkering with the powder charge and pouring bullets into someone else's mould idea, or who has come to the point of wondering if there isn't something he could do about the performance of his projectile that would have a greater effect than nearly anything else he can control . . . for this person, who is an advanced handloader and knows the game, and might even be getting a little tired of its routines . . . bullet swaging offers a startling new field of experience. Practically speaking, the pressure-formed projectile has three
Fitti ng cores to jackets, both in diameter and length, is relatively easy. In handgun calibers, with the lead formed into a nose shape beyond the end of the jacket, there must be enough lead not only to fill the punch cavity but also to permit expansion within the jacket. A 5/16" l ead wire will make good .357 bullets, fitti ng the jacket snugly as seen the back row. It will also make up to .44 caliber but the fit becomes poor and a longer core is needed. A cast .38 bullet makes a good core for a .44 as seen on the left. The extreme rear left item is a .44 jacket with the cast or swaged .38 lead bullet in it.
In the front row are two example of matching cores to jackets. The two rifle jackets are .224 caliber, one with a core extending beyond the jacket and requiring a larger punch for making a lead tip bullet. The other is a normal core for an open tip match or varmint bullet. A fter seating it will be deeper in the jacket. The large .44 cores are fitted to a half and a 3/4-length jacket, showing the proper core length for a normal bullet using t hese jackets.
factory-made, store-purchased jacketed bullet. First, a swaged bullet can be produced that has virtually unlimited performance range from airgun to laboratory light gas/vacuum bombardment gun speeds. It can turn a .44 Special in a light frame revolver into • a defense weapon of few equals, without at the same time endangering neighbors beyond the next wall, by using swaging expansion-oriented designs. It can turn a .45-70 into a deep penetrating medium game rifle where the regular thin jacket or soft nose factory bullet breaks up, using multijacket or protected point or even full metal jacket swaged designs. That old saw about jacketed bullets in handguns not penetrating well on game doesn't have to be true . . . not if the person doing the bullet making knows what he wants and how to get it. In short, there is no aspect of penetration, expansion, velocity, or combined performance that cannot be produced by tailoring the bullet design to the specific purpose. And in no case do we have to put up with barrel leading to do it. Second, the swaged bullet has an advantage over cast bullets in cost of equipment for a given number of bullet weights and styles. Swaging dies and punches are very versatile today. Modern designs allow the swager to make cup base, Minie-ball type blackpowder slugs of all lead design in the same die that makes a flat base Keith semi-wadcutter for the .44 Magnum or a full-jacketed but open tip for the .44 Auto-Mag. Or, for that matter, a rifle style .44 bullet with a wonderfully effective copper tubing jacket, turned over nearly closed at the base and with a nice spitzer tip, complete with hollow point! All it takes is a change in technique and punches. A single set of swage dies can make so many different kinds of bullets (all of the same diameter) in so many weights that one would need a whole fortune in moulds to do half the number. Each shape and weight is up to the person doing the swaging,. right at that moment, by how much lead and how much ogive he wishes to use. Certainly, the handloader can make a terrible bullet by improper design . . . but he can also learn by it and make bullets the like of which have never been offered by any factory, and whose performance is impossible to build into any cast bullet. Versatility makes the cost comparison tip very heavily in favor of buying swaging equipment. Singleminded purpose almost entirely favors casting, so long as the bullet so cast will do the job. Third, the problem of getting lead ready, handling the cast bullet once when making it and again when sizing and lubricating it and again when handloading it is cut to one pull on the handle of the press, starting from nothing but a roll of lead wire (or a box full of cast cores . . . which can make many kinds of bullets) and a box of jackets. . . and no sizing, lubricating, or special treatment is needed. In fact, many people are so amazed when they finally realize how easy it really is to design just about any kind of bullet on the spot,
Three cores, from least to most accurate, are shown here. The fastest to make, and the least acurate, is the cut lead wire core shown at right. It has some weight variation from poorly formed ends and a slight amount of bending. A good core cutter will reduce the amount of deformation and allow more accurate cutting. This one was cut on a very cheap cutter. The middle core is cast in a four-cavity mould. It is more accurate in weight control, has better end forms, and is usually more free from oxidation. The last core may have more wrinkles and incl usions depending on mould temperature and casting technique. It is usually more accurate than cut cores unl ess a highly accurate cut ter is used. The best is the swaged core, made from either of the two other cores shown. It has good finish, excellent end shapes, a/most perfect weight control, and is swaged to ideal diameter for the bullet jacket in which it will be used. Core swaging is ideal for good rifle bullets and usually not required for good handgun bullets.
in love with the process! It becomes a hobby all of its own for a time, just making the bullets the way they were thought up . . . or trying different combinations to see how the bullets will come out. Almost every swager has a bench littered with one of a kind bullets. . . not to shoot, just to see them come out of the die in a new form because of a change in technique. It is a little like a child who is afraid of something in the dark, and who finally takes courage enough to open the closet door. . . then peer under the bed . . . and finally thrust aside a curtain to check the last possible hiding place, fully expecting the worst, only to find the wall. The facts shine out so obviously in comparison to all the imagined problems. In watching a person who has learned to swage bullets, and is starting to realize the powerful nature of the system for designing, it is almost possible to read their thoughts from their expression at times. "Ma n," they seem to be saying, "This is nothing but easy . . . and look at all the things you can do with it!" The myths and years of misconceptions fall away like the slushy snow slips from an elm trunk, in the warmth of the morning sun. Just getting to that point. . . that's the whole problem. The person who has not tried swaging, but is confirmed in factory bullet performance or casting (both of which are admirable faiths and well founded) keeps expecting to hear the catch . . . and there isn't any. Summing up the casting to swaging comparison, swaging is fast, versatile, capable of wide-ranging performance, and low cost compared to equipment for a like number of cast bullet styles and weights. Casting comes up ahead on comparison for a single bullet or at most two or three basic bullets, swaging is ahead for the shooter who likes to experiment or has many guns requiring similar diameter but different style and weight bullets, or has many activities in shooting requiring different performance from his bullets, even in the same caliber... in relation to the cost of equipment. Not in cost per bullet. In cost per bullet, there is no way a person can say swaging with jacketed bullets produces cheaper bullets than casting. That is, if a person does not mind comparing apples with oranges, by saying that we should disregard everything but the cost. If we forget about performance, versatility, equipment costs, and all the other benefits, then by the same comparison rocks are by far the best projectile and the slingshot is much to be desired over the .222 Remington or any other caliber! Well, it's cheaper isn't it? An earnest cost comparison has to take into account the purpose of bullets. If that purpose is simply punching holes in paper, at moderate speeds, then a cast bullet is by far the best choice since no other demands are placed on it. If the purpose is also to make bullets for defending the home, or patrolling the beat, or bringing down the black bear, then probably swaging should be given the nod, even though a jacket costs more than the lead used for casting or for
Lead wire in 3/16 and 5/16 diameters in 25 lbs. spools, shown with the universal core cutter (.17 t o .45 caliber). This is t he fastest way to make cores, and with a high grade cutter such as the one shown, the accuracy is on par with cast cores. The number of bullets in such a roll can be found by dividing the bullet weight into 175,000. For example, one of these rolls (3/16" size) will make 4,375 bullets for the .22 Hornet of 40 grains each. Multiply t imes the cost of the same number of commercial bullets per bullet, and a comparison to lead and jacket cost versus commercial bullets can be determined. Usually the savings is about 40%, although in some calibers it can be much more. Casting cores is even cheaper, but requires a
What about the factory bullet? If there are two and a half reasons why swaging is better, they are as follows: (1) A swaged bullet can be made in any style, weight, and internal design of any factory bullet plus many that are too expensive for any factory production but offer unique performance. The bullet can be tailored to the gun precisely, not. just in diameter, but in exact weight, bearing surface, ogive, and base form that produces the finest accuracy, highest velocity, best penetration, or whatever the purpose is at the moment the bullet is formed. A factory bullet must be a compromise, made for the average. A person should not attempt swaging with the sole idea that he is going to duplicate factory bullets. Usually, he can buy them just about as cheap if he gets wholesale lots. The factory can crank out bullets of a style and weight calculated to sell the most bullets to the users of a given caliber. . . and do it cheaply . . . in comparison to the home swager trying to compete with them for his own consumption. That is, with regular standard styles of bullets. The benefit of swaging is to make those expensive kinds of bullets, or to make ones that work just as well, or b et te r. .. or to make bullets that work better for a given purpose because they weren't turned out to sell to the most people, but to only please one person. So many letters come to the plant where the dies are made that start out with . . . "I don' t think it would be possible to make a swaged bullet as good as the XYZ factory bullet, but I want to make something close to save money . . . " Them's fightin' words, Jackson! The die-maker has more faith in the handloader than that! Don't make them as good . . . come up with one better. In fact, fill the top of the loading bench with bullets until one comes up that outperforms anything a standard production bullet ever thought about doing. That's the spirit of swaging! So much for the first reason to swage. Number two (2) reason is that in many cases one simply cannot buy the caliber, or weight, or style, from anyone for any price and swaging is the only practical way to make the bullet. Someone in the back yells "Oh , yea? Name one!" about this time, since we do have a wonderful selection of factory bullets thanks to a lot of fine firms in that business. At this time, there is no Speer .20 caliber bullet. It is easy to swage, and jackets are a snap. There is no 150 grain 9.3mm in the Hornady chart. However, a .38 jacket swages up fine in the right dies. It would be difficult to find a Sierra 90 grain 7mm with a nice hollow point similar to the 100 grain Speer Varminter. Or, for that matter, any other brand. A 6.5mm jacket can easily be expanded to make a fine varmint 7mm bullet. The soft point with a bigger hollow point than any factory bullet of a similar type is also a simple job, done while expanding diameter of the jacket, and simultaneously with forming a cup base, if desired, or boattail.
A battery of air gauge columns, part of the air gauge system f or precisi on measurements of die cavities. The columns are the readout devices, which act as guides for a spinning pointer suspended on a column of moving air. The rest of the system incl udes a complex chain of regulators for the air, a connecting flex hose, a small steel plug that is inserted into the die to form a nar row channel between the die walls and the plug thr ough which air escapes, and the air supply. Escaping air pressure controls the position of the spinning pointer as it fl oats in the columns, giving direct readout of tolerances over and under a standard diameter of cavity. Resolution t o l ess than 10 milli onths of an inch is readily achieved on the right hand column, and to direct scale markings of 40 millionths. Using a micrometer on the bullet does not usually give the cavity size of a die, since f inish, pressure, lube, and shape will control t he diameter within the cavity. And, an air-gauged die does not necessarily give the same diameter of bullet as another with identical cavity si ze for the same reason.
around? No, but again that's a swaging job . . . even without a jacket commercially available, the good old thin-wall copper tubing cumes to the rescue. For that matter, what about a 60 grain full metal jacket 6mm Remington bullet for those fur-bearing critters? Sure, the FMJ bullet is available to the swager, using the right technique. And if there is no cup point but full jacket .44 Special bullet that offers extreme expansion at modest speeds, yet won't go through walls with any resolve (as noted in many recent articles), it is not the fault of the advanced handloader who swages his own. Now for that half a reason that swaging is better than always buying factory bullets. A direct rebuttal from many prominent writers would result, undoubtedly, if it were mentioned that accuracy of the home swaged bullet can in many cases be better than the factory projectile. The benchrest group is best able to speak on this, since this group has long had the experience of using both swaging and factory bullets, and today is just about mixed on the selection. So it will not be said, and no problem shall arise. However, it is very evident that a person who assembled his own bullet is in a good position to select and control what goes into it, how it is made, and then to judge afterward whether it shot better or worsethan others he has tried. If the bullet is neck and neck with factory super match bullets, to the point that no fu rt he r impr ove ment would cause any change in the score since other factors are now greater. . . maybe even wind doping . . . then perhaps there is no value in the use of swaged precision bullets per se except perhaps a little more cost for the precision factory bullets, offset by the time to make the swaged bullets. But suppose there is a change in technique and the shooter finds that with a half thousandth undersized bullet, his gilt-edge rifle acquires a little more gold . . . just a touch . . . and all of a sudden his groups have fewer fliers. Many a benchrest shooter has expressed their rapture at a similar discovery, virtually planting a big kiss on the side of th at old swaging die, because they have learned something .. . no great universal truth, it is true . . . but just a facet of pinpoint shooting which applies to their particular barrel, and makes enough difference to pay for all those hours spent at the bench, putting lead into jackets and wondering if there was really any advantage to it, when just everybody said XYZ brand was just as hot as anything that came out of a swaging die and only a dime a bullet, delivered. The little extra snicker comes from our happy swager adding up all the two cent jackets and two tenths of a cent of lead wire he has used, and subtracting from the match bullet cost. Ordinarily, who cares about that when it comes to match winning? But it's nice to win and save, both. But that's only half a reason because we are back to comparing apples and oranges again . . . and the main reason for swaging is
of all the brief summary between casting and swaging benefits, and buying factory bullets. When all is said and done, few advanced hand loaders do not do all three. Most swagers, cast. Most casters buy factory bullets too. Rare is the person who restricts his bullet use to swaging alone, and never buys ready-to-shoots at the store, or dusts off the old lead pot. In fact, most handloaders probably don't quit buying factory loaded ammo entirely. Chances are they shoot more and possibly buy more than the average non-handloader. So it is with the three methods of obtaining bullets.
Various forms of the round nose bullet. The long bullets show round noses with various degrees of exposed lead. The bullet at the rear has the core brought almost to the end of the jacket but is not a true soft point round nose. It is almost a transitional style between open and soft points. The middle row of bullets show the use of the round nose to gain better bullet balance in short styles. The fat .45 bullet needs a low-number ogive in order not to be all nose i n this weight. The two .224 bullets show the use of round nose rather than spitzer to gain weight ( middle) or to give better bearing surface in a li ght weight (end). The handgun bullets on the right are made with round noses but the two with step shoulders are made in a single die. The one wit h the jacket brought into the ogive had the core seated inside with a round nosed punch, turned down to fit the jacket. It offers positive f eeding in
TECHN ICAL BU LL ET IN 1-3-76 Special Note on Die Adjustment and Excess Pressure
Designs of bullets for penetration, using various swaging t echniques. At the back is a two-jacket bullet, using a half jacket and a three-quarter jacket to make a capsule, formed into a hollow point wadcutter. The same technique can be carried further with a small jacket inverted over the core within a larger jacket, making a partition or protected point bullet. If there is a core put over the internal jacket, a two-core bullet results. If the single core is made large enough so that the small jacket base forms the bullet nose, then a protected core bullet results. The middle row shows inverted jacket, open base bullets (not normally recommended for swaging, but can be done with the right jacket materials). Also, two bullets with gas checks swaged over the nose, inside the jacket, are shown. The front row shows other styles for making delayed expansion, deep penetrating bullets. This includes a holl ow point formed in the jacket, inverted. Bringing the jacket to a point, or covering most of the core with jacket, then putting a gas check over the end within the jacket, are fairly easy styles of "advanced" swaging technique
Damage to reloading press ram tops, dies, and punches can result from incorrect adjustment and operation of the bullet swaging dies. Corbin dies do NOT require throwing one's weight on the press handle, and allowing the ram to pass over center regardless of the setting of the die may ruin both the dies, the punches, and the press ram. To correctly set up any die, start with the die just barely screwed into the press. In core seating, put a lead core (soft lead only) into a jacket and place the assembly on the core seating punch, which is in the press ram. Raise the ram all the way . . . the die should be too high for the jacket to touch bottom. Screw the die down until it meets resistance against the jacket. Lower the ram and give the die a very slight (1/8) turn down. Raise the ram and feel the pressure required, so you can compare it to other cores and jackets. Lower the ram. Notice if the jacket stays in the die, or come back out with the punch. If the jacket and core come out with the punch, lower the die another 1/8 of a turn and swage again. Each time, notice the pressure it takes. It should be very slight, never straining the arm. When the jacket and core stay in the die after the ram is lowered, use a plastic hammer and tap the knock-out ram to eject the seated core. Notice if the jacket and core come out with a mild tap, or if a rather hard blow is required. If a hard blow is necessary, the jacket is dirty, oversize or too much pressure was used. The right force is just a little more than can be comfortably applied by the hand alone. If the core falls out and the jacket stays in the die, the jacket is oversize. Examine the lead in the mouth of the jacket. It should touch the jacket walls, and have just a faint (0.002-005") rim of extruded lead coming up the walls at most. Any significant amount of lead moulded onto the jacket walls indicates too much pressure, too small a punch for the jacket, or too heavy a core for the jacket/punch combination, since commercial jackets taper internally. The seated core and jacket should beat least 0.0005" smaller than the finished bullet, and can be as much as 0.002" smaller without too much difficulty. The very base can be as much as 0.0003" larger than the area immediately above the base because of the pressure ring effect (the base is a solid copper disc in cross-section, while the rest of the bullet is a copper washer with lead behind it). Miking seated cores will tell if not enough pressure has been used (undersized) but not if too much as been applied . . . until the die swells and is ruined. Remember to use just enough to do the job as described above . . . no more! Die, punches, and ram tops will last for years of hen good practice is employed in swaging bullets
TECHNI CAL BUL LE TI N 2-1-76 Rimfire Jacket Chracteristics
Close view of four styles of bullets made to penetrate more deeply than t he usual swaged bullet. The inverted jacket, the multiple jacket, t he cup point multiple jacket, and the partition bullet with a cup nose are shown. Jackets can be telescoped within each other in various ways t o make such bullets. On .224 and 6mm, fired primer cups can be used within the normal jacket. On larger calibers, shotshell cups or small rifle jackets or gas checks can be used to form expansion-delay walls.
Rimfire jackets made from fired .22 Long Rifle cases have been used since the beginnings of home swaged bullet-making. Many early experiements were less than satisfactory because of two conditions no longer existing today; mercuric priming and soft copper cases used in the old rimfires. Mercuric priming caused embrittlement of the cases, so that the jackets would fly apart in a most unpredictable manner. The soft copper cases were both a blessing and a serious problem. They drew easily, forming good points with little difficulty even in dies which were far below standard finish and tolerance. When high pressure .22 rimfire loadings and smokeless high velocity rounds required a tougher brass (copper alloyed with a small amount of zinc, which is more nearly like commercial jacket material) the equipment which made good bullets with soft copper jackets no longer did the required job. Another problem was that the soft copper made good jackets but tended to foul the bore of higher vefoci'ty rifles. The problem of inaccuracy with mercury embrittlement was carried forward with further inaccuracy from copper fouling, causing a general distrust of the .22 rimfire case among experienced shooters. Although the attitude has carried long past the cause, today's modern .22 cases make good jackets providing that they are annealed and cleaned well. The usual fired .22 case measure about 0.228" OD , and in order to remove the rim and the mark left in the case by the rim, it should be drawn to about 0.219" OD. A draw die with a 0.218 hole will produce such a jacket. The punch should be held toO. 196-0.200" OD. If dirty jackets are used over a period of only a few hundred rounds, the punch and/or die will be scored and worn a few thousandths of an inch, causing the jacket or case head to fold rather than iron out. If the head folds back on itself it will make a jacket in which the base area is not evenly drawn, and this will usually cause some inaccuracy in the bullet. Cases should be cleaned in hot soapy water, dried and annealed, and cleaned again. Primer residue can be removed by wiping inside the case with a swab before drawing. A water-soluable high pressure lubricant (lanolin or Draw-Die Lube) should be used inside the jacket to cut down punch wear. The generous application of lube will also act to fill the head under drawing pressure and help insure even drawing. Drawn cases should be washed soon after forming, and dried well before seating a core. The normal 0.705" commercial jacket for match bullets of 52-3 grains is a close match to the rimfire case after drawing (.22 LR). Using a .22 LR for a 6mm jacket usually means that a certain amount of lead needs to be exposed in order to gain an adequate weight for the caliber. The lead should not touch the rifling, but will
normally form about half the ogive of a 6-caliber ogive spitzer in an 80-85 grain bullet or less than a third of the ogive in a similar 65 grain bullet. The rimfire jacket with exposed lead tip bullet is extremely explosive on impact, because of its very thin and untapered walls. These bullets should not be used for medium game. They are suitable for varmits and target shooting. The velocity range of 3200-3400 fps is the marginal area of performance for rimfires, and should generally not be exceeded.
Bullet Jackets are normally purchased in lots of 250, 500, or 1000 depending on their size and bulk. In the smaller rifle calibers and all handgun calibers, the 500-lot bag is a common size. Jackets are normally sold in a given length, accuratel y trimmed and ready to use. Untrimmed jackets present a problem to the home swager, who must trim off the ragged ends to a suitable length without creating too much of a handling problem or making bad burrs or marks on the jacket. A lathe, a case t rimmer with collets to fits, or a pinch trim and draw die are answers suitable for home use. Generally a jacket must be drawn slightly down in diameter to pinch trim properly in a single die. A .243 might be drawn down to .224 and trimmed in the same die. Fortunately, enough jackets are available to take care of nearly any standard caliber and length while some variation in core length is acceptable to make different weights in the same jacket.
TECHNI CAL BU LL ET IN 3-4-76 Hollow Point and Cup Base Bullets
A valuable set of dies . . . hand-fitt ed diamond lapped dies can be made in any caliber (odd calibers such as .20 and 9.3mm as well as any standard size) if a special press is used with threaded ram. Slotted ram reloading presses generat e plenty of pressure, but don't have the ram strength at the slotted stop secti on to take extreme forces. The press itself is strong enough in the frame and leverage, of course. This picture illust rates the floating alignment punch holder in the press head, variabl e-pitch lock ring which does not marr the press or die thread, and the fit of custom dies in the Mity Mite press. The die being held shows the approximate l ocation of the threads i n the die which is shown in the press ram. A shoulder
In conventional swaging dies, the hollow point bullet can be formed by using a punch which has a pin inserted in the center of its cavity. The nose is formed of lead entirely, with the jacket remaining straight (no ogive covered by jacket), in most of these dies. The lead nose is formed at the same time the pin is pushed into the lead. There are three problems with this kind of arrangement. First, the lead tends to stick fast between the side of the pin and the walls of the nose forming cavity. Second, there is no place then for a bleed hole in the center of the cavity, meaning that a side-bleeding die has to be used. These cannot make 3/4 jackets, but only the 1/2 jacket style of bullet with some lead in the parallel section of the bullet (where the bleed hole must be located). Last, only one depth, taper, and size of cavity can be made with any given punch. An interesting variation which solves all these problems and does NOT require special equipment (but may take an extra step in swaging) involves the use of the cup base punch. Inside the die is a punch which normally forms the base of the bullet. If this punch has a raised center portion, it will impress the jacket base and form a shallow cup. If the bullet is formed so that the NOSE rather than the B A S E is inserted first into this die, then the nose will acquire this cup. It will of course be a wadcutter at this point, with a cup in it. To push the bullet into the die "backward" a normal flat wadcutter punch is used. This is then the same as a normal flat base bullet punch, as it presses on the jacket. The lead tip can be formed into a wide range of cup or cavity point openings, or even closed completely, by reswaging the same bullet in the normal manner. Eject it, turn it over, and using the normal nose forming punch, press the bullet back into the die. By carefully stopping short of complete reswaging, an unlimited range of adjustment of the cavity size and bullet shape (between full wadcutter with cup point and normal punch shape point without any hollow point left) can be made. Since a straight-walled die uses nose punches which must have a small step between bore diameter and the beginning of the ogive, the less completely reswaged bullets will also have this shoulder impressed into the nose area. To eliminate this effect, the cup-point wadcutter bullet can be ejected and reformed in an ogive-wall die, which has no steps and can bring the jacket as well as the lead around a curve. Highly effective hollow points can be made in this way, which eject easily and are controllable over a wide range of shapes, depths, and opening sizes. Another method uses a separate punch which can be inserted into the lead nose AF TER the bullet has been formed normally in the
changed, the tapered pin punch pushed up into the cavity of the die, and then the bullet is ejected. A very slight pressure will form a small cavity, with larger pressures forming deeper and wider hollow points as well as rounding the nose by moving the lead back toward the die walls. This bullet can also be reformed in the ogive-wall die, which will yield unusually deep and even bottle-shaped cavities. The cup base in a handgun bullet can serve several useful purposes, provided it is kept in a reasonable depth and shape. So long as the cup is not too deep, it will safely permit the base of the bullet to expand slightly when the bullet passes from a revolver's cylinder to the forcing cone of the barrel. In a jacketed bullet, with flat base, the jacket often does not permit enough expansion to prevent gas cutting of the revolver frame. This is the main complaint against jacketed handgun bullets in revolvers, and it is easily solved by the use of a properly-shaped cup base punch. Gas cutting may occur because the forward part of the cylinder is too large to seal gas as the bullet passes through it toward the barrel. A jet of hot gas escapes around the bullet, is deflected up against the top strap of the revolver frame as it escapes from the barrel-to-cylinder gap, and eventually may show signs of gas cutting. A lead bullet without a gas check can expand to fill the forward part of the revolver cylinder, the swage down again in the forcing cone to fit the bore. A cup base jacketed bullet can do the same thing. The danger with either lead or jacketed bullets is that a very deep and large cup base could permit the base to expand so much, and so far toward the middle of the bullet, that a lot of pressure would be generated against the forcing cone in reswaging this amount of bullet, possibly even cracking the barrel or frame. These are remote but still possible chances, and are reasons why well-designed cup base bullets should always be used, not merely any sort of base that strikes the fancy. With a normal, shallow cup base using the proper amount of thickness between walls and start of the cup, the base will expand only enough to seal gas and notenough to cause any other problem. The cup base also permits the weight of the bullet to be less for the same length. This is valuable in some auto loaders. For example, in the .32 ACP caliber the performance of the gun and bullet is greatly helped by the use of a lighter bullet with a step shoulder between the jacket and the pure lead nose. But the over-all length of the bullet should be at least that of the factory ball round, if not more, because it needs more bearing for alignment in the bore than can be achieved with a normal ogive for the caliber. By using the cup base, a small amount of lead is shifted forward to use in the nose portion, and the over-all length remains the same or longer than factory bullets. The result is superior accuracy, as well as the higher velocity desired to produce better impact performance.
The cup base also produces a slightly higher pressure with the lighter bullet than a flat base, which helps insure reliable feeding with the less-than-normal bullet weight and complete burning of the powder in the barrel lengths normally used for small automatics. These effects are slight, but significant. The same effect may be noticed on all calibers up to the .45 ACP. The cup base is not normally recommended for use with very heavy swaged bullets as the effects then act against the desired results. For example, in a .380 pistol one might wish to use a cup base on an 80-90 grain bullet but not on a 95-110 grain bullet. In a .25 ACP pistol, the cup base is ideal with nearly all bullet weights from 45 to 60 grains because the bullets are normally so short and the bores vary . . . accuracy can be helped by a bullet which does not wobble down the barrel, and impact shock increased by a large pure lead tip with step shoulder to hit with full bore diameter.
A few of the base shapes other than the ordinary fl at type are shown. Cup bases are easy to make duri ng the core seating operation, whi le the boat-tail types requir e extra dies and punches for proper forming. Usually it is best to preform both t he jacket and the core, which involves more costly equipment than eit her cup or flat bases. A slight rebate and boattail of smaller proporti ons can be made at less expense, eliminating some of the preforming operat ions. Open base .224 (.223 Military) bullets and some .30 caliber open base bul lets can be made much more accurate by simple reswaging in a single point forming die, to bring the base to a smooth and even fl at or cup form. Many such bullets have ragged, poorly filled bases that cause erratic grouping and be brought into better accuracy by
TECHNICAL B UL LE TI N 4-22-76 Bullet Jacket Design & Selection
A number of problems can arise in using various kinds of bullet jackets in home swaging, many of which are a matter of selection with a micrometer. Several brands of bullets are made by swaging down in the last step, which is a good way to insure a parallel sided bullet as the entire bullet passes through a draw die and is drawn down slightly all around. This is still done in some plants because (1) it is easier to eject a tapered bullet from a die and then draw it parallel-walled later, (2) the method of lapping dies tends to make them tapered larger toward the mouth in any case, (3) tolerances can be much "easier" to maintain because they are not so critical if the bullet is going to obtain its final diameter in a precision annular die by drawing down. The problem this creates for the home swager is that such bullets are usually made from jackets which are either at or over the desired finished bullet diameter before any lead is installed. Bullet jackets purchased in bulk from overruns or special draws can be a good bargain for a supplier, but he must be careful that the outside diameter is not already at bore size or the home bullet swager will have problems. The jacket for swaging in the home or small custom shop is supposed to be filled and brought to size in only two swaging step s... a thing many production plant managers still find hard to believe, after working with six and more progressive draw and swage steps to accomplish the same thing in production. But the home swager has to make sure his jacket diameter is correct to accomplish the desired results. The jackets used by home bullet swagers will be put into a core seating die that is about half a thousandth of an inch under finished diameter. The jacket must then be able to slip easily into this hole . . . meaning at least a half thousandth smaller O.D. . . . and it must stretch slightly with the pressure of the lead, so that when swaging pressure is removed from the core, the assembly contracts slightly, releasing the intimate contact grip on the die walls. Otherwise, the jacket will not release or will try to spring back to the large diameter, assuming it was oversize for the die. This will make ejection very difficult. Also, since home swagers usually reject the idea of drawing a jacketed bullet down (which, if done excessively, will result in a loose core and poor accuracy) to create high precision, parallel sidewalls, the dies themselves must be quite parallel of walls. This places even more stringent demands on the tolerances of the jackets to permit ejection. Thus, jackets obtained through some bullet manufacturers will tend to be oversized for the caliber in home swaging, and ought to be miked and either drawn down in a first-operation drawing die before 1
draw die for the bullet, like the factory bullet. While this has been blamed for poor accuracy, the draw-down, like any other part of technology (or life!) can be good or bad depending on the amount used. It is excessive drawing that is bad, not just the fact of drawing the bullet down. The up-swage principle which was developed by B&A Dies long ago was to counter the really excessive amounts of die taper which used to be used before manufacturers realized what the jacket springback was doing in creating a loose core. A draw-down to a finished bullet of 0.002", for example, would certainly exceed the limits of the jacket's "spring" or elastic modulus for most copper-zinc alloys, and result in a loose core. But a draw-down of only 0.0005" would generally improve the parallel features of the bullet, give it a slight polish, and for a jacket which had previously been expanded almost 0. 001" anyway, not loosen but perhaps even tighten the core (as the metal is moved into areas of small cross section from areas of larger ones, placing a heavier internal pressure against the lead). In any case, the jackets which should be used by home swagers today with the two-die, up-swage type operation, should never be at finished diameter before any lead is installed. While these may work, they also increase the chances of sticking in the dies and do not make the best looking or shooting bullets. The question of weight versus core or jacket length is a bit tricky. Many die or jacket sources advertise, for example, the 0.705" bullet jacket in .224 caliber as being a 52 grain jacket. This is the original weight of bullet for which the particular jacket length was designed, but it by no means is the only weight that can be made. The lightest weight for any jacket length is the length of seated core which (1) permits the core seating punch to contact it in the particular die set, (2) permits the particular weight of jacket (wall thickness and alloy) to form a good nose shape in the ogive or point forming die, as some jackets will not follow the die wall unless backed by sufficient lead, (3) allows the bullet to remain stable in flight. The only way to say for sure if a bullet is too light for any of these requirements in a given jacket length is to make one and try it. Many rather odd combinations of lead and jacket seem to work out fine if the materials happen to work in the dies and rifle. The same goes with a handgun bullet except for the semi-wadcutter style of die, called the straight wall die because the jacket is not brought into the ogive or nose curve. In this kind of die, the nose punch presses the extended core into the desired shape. The core must always be longer than the jacket. Hence the minimum weight is determined by the jacket length. A so-called "half-jacket" may be ideal for light-weight SWC style bullets that are actually 3/4-jacket styles. The heaviest bullet that can be made with a given jacket is entirely determined by the amount of lead exposed at the tip. Any jacket can
extending the lead far enough beyond the end and using a larger punch to "seat" this core. So a .705" length .224 jacket can actually make a 75 grain bullet or so, if a person wants that much lead exposed (and the die length will hold this much lead and still align the punches). In general, the nominal weight given is the best weight for a jacketed bullet in which there is no lead exposed, but not much of a cavity or area void of lead behind the jacket tip. It isn't necessarily the best for performance. But is is the "popular" version of a bullet made in that jacket.
TECHNI CAL BUL LE TI N 5-25-76 Illustrations of Bullet Length & Weight in HG Jackets
Various lengths of jackets used with similar shapes and weights of cores. In only the scales can really tell much difference. In others, the resulting bullet too long for the styl e, jacket, or for good accuracy in the gun. Jackets are making just the kind of bullet after which they are named, however, and bullet weights and shapes work out very well.
The effect of using too large a core ( too heavy) for the jacket and the amount of tip closure bf l l Mt Jdhw Within the point forming die, the excess lead will extrude up theject.o 1 n Jto £%,king a lead pipe on the end of the bullet. Then, when election pin will bear on this lead pipe and make it into a mushroom at the up of the bullet as soon as th^bullet moves clear of the die cavity. No harm is done since the excess lead can be capped off. Adjusting the die higher so that a more open pomt ,s formed mil usually solve the problem even if the same weight is retained.
^ff ^Vff ^
some instances, is too short or not restricted to some unusual
Handgun jackets are commonly sold in the so-called "half-jacket" and the "3/4-jacket" lengths. These terms refer to the length of the jacket compared to the usual weight of bullet for the caliber. That is, a half jacket bullet in .38 caliber might have a weight of 158 grains and half of the total bullet length would be covered by the jacket wall. But this does not preclude other weights or designs for the homeswager. The newest jackets which are now available from Corbin and other swaging supply houses are the handgun "f ul l" jackets. The term also needs clarification. A true "full" jacket bullet is usually made by the factory by placing the base of the jacket into the nose forming die first. The open end of the jacket becomes the bullet base. This is the usual design of a pistol bullet such as the .380 or .45 ACP. However, for the home swager, this jacket will make the heavier weights of "semi-wadcutter" style bullets and still retain the full wall coverage of normal weight 3/4-jacket bullets. They will also permit the swaging of "ogive" wall bullets . . . bullets made in a die with no step or shoulder between nose and cylinder portion of the bullet. Here they can be used to great advantage in making either normal weight or light weights. In the illustrations above, three jacket lengths are shown. Column 1 shows a bullet made in each jacket of the same weight. Note that the lightest weight that can be made in the "full" jacket makes 3/4
and 1/2 jacket bullets with lead touching the rifle or handgun bore. In column 2, the minimum weight of each jacket in the usual "semi-wadcutter" type of die (nose formed in a punch inserted from the bottom, against the lead core only) is shown. Each jacket has a mimimum weight equal to the amount of lead that still permits a full nose to be formed with the jacket contacting the bottom punch. Note that in the half jacket, the bullet becomes so short as to be unstable in most calibers with any reasonable nose length . . . if the minimum weight for a semi-wadcutter style die is made. Column 3 shows the use of a trunicated conical style of ogive-wall die with the same bullet weight as Column 2. Now there is no lead touching the bore, and a proper shape of nose will permit bullets which are reasonably designed for any of the three jackets. Using less lead for the core results in bullet like those of Column 4. The half jacket makes the very lightest bullets for the caliber, the 3/4 jacket makes more reasonable (stable) bullets in this style, and the "f ul l" jacket creates more nearly conventional weight bullets but still can make bullets of lighter than normal weight by closing the nose to a greater extent. Thus it can be seen that the bullet swager should select jackets not merely by the common name given them, but by the weight and style desired. The use of higher velocity loads may indicate shorter jackets for the semi-wadcutter style of bullet die (or straight-wall die) but the longest jacket can be used to good advantage in ogive wall dies. The jacket length will help determine the rate of expansion. Thus, a long jacket in the ogive-wall style will help to control expansion at high velocity, while the shorter jackets will enhance expansion. The swaging of factory-style "full" jackets in conventional two-stage or single-stage swage dies is NOT recommended. The base should not be inverted. Jackets made for use in high performance swaged bullets such as those illustrated in the " ful l" jacket style have a tapered wall and a thick base. This base will resist swaging to a point. It is thick to resist the pressure of a hot load against the base, which can cause complete blow-out of the core and base if the entire jacket is made thin enough for good expansion. The jacket will grip the walls while the base will deform inside, toward the core, under high pressure loads. If the base is not made thick in relation to the sidewalls, it can actually fold so far under the pressure of firing as to rupture and leave the walls of the jacket in the bore. The tapered jacket is a modern development for handgun bullets and permits both good expansion with mild loads, and safe use with very high pressures. Most rifle jackets, being long in relation to diameter, are drawn with an internal taper in the smaller calibers, and with a two-step cylinder-conical inside dimension on larger calibers. In swaging any handgun bullet, it is important to start the bullet carefully into the die by hand, and to guide the punch slowly into
the mouth of the die. Most of the initial damage done to punches by a beginning bullet swager results from careless use of the punch, allowing it to strike the mouth of the die. A second common damage occurs when the swager attempts to make too light a bullet for the jacket length, permitting the thin edges of the nose forming punch to strike the jacket mouth. If reasonable pressure is applied, the jacket will buckle before the punch is harmed. Slow, gentle technique should always be used when adjusting dies and testing various core lengths in given jackets.
Various forms of cup base bullets. These are formed by using a domed punch in the core seating die and a matching punch in point forming. In the back row are a pair of rebated base, cup base bullets, which have a step or heel just at the base. This is done by pressing the base with a standard nose forming punch, gently, before applying pressure to a cup base punch. While easy to do, there is no parti cular advantage. In general, high pressure loads should use shallow cups while lower loads may go t o deeper cups with the edges near to the bullet walls. A small cup just in the center helps to force air out of the jacket, since this point contacts first in core seating. It serves little ballistic purpose. The cups which extend more nearly to the full bullet diameter have many uses. They help seal the bore, make it possible to use an undersized bullet with reasonable accuracy and better velocity (as when using one set of dies in several guns with slightly dif ferent bores . . . not all .38 Specials have exactly .357bore, offer some improvement in accuracy when the bullet is a bit too light for the caliber and has little bearing surface (as with .32 and .25 ACP bullets), and have other advantages in some uses. In the front row is a full-metal jacket bullet with an open base. The jacket extends beyond the core, but this is not really a cup base bullet A cup base in the
TECHNI CAL B UL LE TI N 6-10-76 Comparison of Casting and Swaging . . .
In order to help dealers and handloaders explain the differences in swaging and casting in terms of technical performance, cost, and reasons to select one process or the other for a given purpose, this technical bulletin has been prepared. It is necessarily brief and generalized, and there are exceptions, but it does give a fast guide to the technical reasons behind swaging. I.
Advantages of Swaging A. Versatility 1. One die makes many weights and styles 2. Diameter and style can be changed slightly for best performance 3. Many kinds of unusual techniques for special purpose bullets B. Range of Performance 1. Total spectrum of velocity without leading 2. Extreme range of expansion over velocity due to soft lead core and changes in jacket, point, and style possible 3. Penetration can be tailored by style of jacket and point design over wide range C. Control of Accuracy 1. Minute weight and style changes possible 2. Precise control of diameter and base style 3. Generally free of air inclusions and bad base D. Cost of Equipment Moderate 1. Ratio of weights and styles to equipment cost very good 2. Use of existing press saves all but cost of dies 3. Cores cut from lead wire require no other equipment (dies & punches only) 4. Core Mould favorable price to Bullet Moulds, wider range of calibers and weights
11 Advantages of Casting A. Low Cost of Bullets 1. Lead & lubricant are the material costs 2. Not necessary to use only pure lead; many available alloys cast well. B, Familiar, Simple Technique 1. Relatively good bullets made by use of mould, pot, lubricator/size only 2. No spoilage as bad casts are remelted (jackets if swaged are not usable again) 3. Easily learned procedure
C. Performance good in Low Velocity Spectrum 1. Low velocity penetration good, due to use of harder alloys for casting 2. Accuracy in most handguns good in low velocity region 3. Hard alloys extend usable range over entire handgun, low intensity rifle range of velocities III Bad Points of Swaging A. Higher cost per bullet B. Longer learning period C. Higher equipment cost for single weight & style of bullet IV Bad Points of Casting A. More danger from burns, lead fumes, then using lead wire cores B. Requires different mould for each change of weight and style bullet C. Limited range of performance for cost of equipment, for making other than single weight and style in a given caliber Some of the details behind factors of comparison are: Speed of Production . . . With cast bullets, it is easy to overlook that one must not only pour the bullet, but must have waited up to half an hour for the lead to melt, properly fluxed the pot, then heated the mould and periodically inspect and reject a number of defective casts. Afterward, the bullets must be sized and lubricated. Usually, they are slower to load, though this is not taken into consideration. Swaged bullets made from cut lead wire and jackets are a one-step affair for handgun bullets, two steps for normal rifle bullets. One can set up the dies, cut the cores, and finish swaging the bullets while the lead pot is still waiting to melt the lead for casting. With cast cores, there is still a speed advantage to swaging. First, the cores are not nearly as slow to cast as bullets. Imperfections are not quite so critical and there are no grooves to fill out, so the casting goes much faster. Of course, with match bullets for rifles the speed is not even considered and cannot be compared to casting, as no cast bullets are ever used for benchrest work. But to make 100 bullets ready to shoot, swaging is usually faster than casting and the quality of bullets equal. Another advantage with swaging is that the same 100 cores can be used at anytime to make small lots of bullets, each one different in shape, and with some difference in weight and caliber possible. The 100 cast bullets are frozen exactly as they are, except for running through a sizer and lubricator which can modify the diameter slightly. Not considering the making of cores, swaging is much faster than casting. Thus, a stockpile of cores will make it possible to swage on a moment's notice, without even needing a half hour to make the lead ready. There is no way to achieve this spur of the moment production or changes in weight and style with cast
Cost of Equipment for Given Versatility . .. With cast bullets, a separate mould is required for each weight, style, and caliber of bullet. With swaging, only the caliber stays constant while the weight and style can be changed within rather wide margins for a given set of dies. The cost of a single mould, to make a single weight and style, is lower than the cost of a set of dies for the same purpose, and the cast bullets are cheaper by at least half the cost of the jacketed bullets. But the comparison does not end with just the mould and the dies . . . the cast bullet also requires a lead pot, ladle, lubricator and sizer, dies and punches for the sizer, and lubricant. Adding all the costs of casting usually equals or exceeds the cost of a single handgun die and punch and a core cutter. The loading press is already used for loading either bullet into a case, and is not an additional cost for swaging. A two-die set or accessory items such as rifle core swage will slightly exceed the cost of casting. But only for the one bullet weight, caliber, and style. When the handloader has to choose more than one bullet weight and nose style, for a given caliber, then the true economy of swaging comes to light. The same die with no additional costs will make a wide range of weights. Each cast bullet means another investment in moulds. A few dollars for a new nose punch, or for a different base punch, will permit a whole different bullet style with swaging. In addition to the use of a different nose punch or core weight for style and length changes in the bullet, swaging also permits the use of more than one punch in succession on the same bullet. The use of cup base punches for nose forming prior to using the nose punch permits a wide range of cup and hollow points with pear-shaped internal cavities. Combining these techniques with the use of both straight and ogive wall dies in handgun calibers multiplies the number of styles possible at a given price for equipment. No such opportunity exists with casting. Performance Limit ations... The cast bullet faces a problem of having to be hard enough to resist base melting, bore leading, and shape change during firing and yet have contradicting performance characteristics such as good expansion at low velocity or moderate velocity. At the higher handgun speeds, it is possible to walk the thin edge between bore fouling and poor accuracy, and modest expansion characteristics. But after a narrow range, leading takes over and no kind of usable performance results. The swaged bullet has been criticized for too rapid expansion, due to its soft lead core.But this is the fault of factory bullets having been mated to loads which appeal to the visual rather than the technical qualities expected by the public. A large soft point with a large hollow point is normally mated to a hot load in the .44 and .357, providing fine shows on informal targets and fairly good use for police, but terrible performance on big game. The handloader who swages bullets can make jacketed
projectiles with tightly closed tips, or swage a smaller jacket into the tip to protect the lead. And, of course, he can swage any other kind of tip or style desired to match performance to the use and velocity. Swaged bullets are outstanding performers for both low velocity handguns (due to good expansion without leading in the wide open, exposed soft tip designs) and in the fastest magnums (due to no leading, and ability to tailor performance by selecting proper style). Accuracy - the largest point of con tention... It has been generally accepted that cast bullets are best for target shooting in revolvers and in old time rifles, and jacketed bullets best in hot loads and all modern rifles. This is simply not true. Many old worn bores shoot best with jacketed bullets due to less leading and fouling. Many hot handgun loads are very accurate with hard cast bullets. At the lower end of velocity, nearly any rifle can shoot well with a good cast bullet. And the use of a cup base on a swaged jacketed bullet permits use with low velocity loads and good accuracy in many handguns. . . though it is true that some guns will not shoot well at low (mid-range) loading with jacketed bullets. For most target shooting, expansion and penetration are of little or no consequence . . . therefore, cost per shot, using only the one bullet weight and style for years of shooting, indicates a cast bullet is the best choice. If higher speeds and a choice of styles is indicated, or use with expansion and variable penetration is needed, then swaging will provide the best answer. In either case, accuracy can be equally good. In neither case will accuracy be good if some careful work and testing is not conducted, and this is slightly more critical with the swaged bullet since there are so many more things possible to try.
TECHN ICAL BU LL ET IN 7-10-76 Core Swage Die Adjustment & Use
The core swage die is also known as a "squirt di e". It is a cylinder type of die, with two punches of close fit, and one or more small holes around the middle. Lead cores are cast or cut to nearly the desired weight, and then all variation is swaged out of them by extruding excess lead through the small holes. The pressure generated is very high. The loading press or swage press is adjusted so that the correct weight of core is left in the die, just as the press reaches the top of the stroke. Setting the die closer to the ram makes a lighter core. But the swage should not be used just to adjust core weight; it is only to remove weight variation. Forcing more than a few grains of lead through the holes at one time is very bad on the die, and can cause the tool steel to fracture. All core weight adjustment should be made when the cores are cut or cast. To determine core weight, weigh the jacket and subtract from desired finished bullet weight. The difference is the final core weight. To determine the lightest weight that will result from normal casting or cutting operations, and thus to determine how much extra lead to cut or cast for proper adjustment of the core swage die, set the cutter or mould to make a core of the final weight desired. Then cast or cut ten more cores without change in the setting of mould or cutter. Weigh the cores, and determine the lightest core weight. As an example, let us suppose that a 52 grain bullet was desired, and a six grain jacket was to be used. We would then have wanted a 46 grain final core weight. The cores might typically have ranged from 45 to 47 grains as cut, or 45.5 to 46.5 as cast. We would take the difference between the lightest core and the average core, which is the sum of all the cores divided by ten, and add this value to the average core weight. Then, we would add another grain to provide a buffer against the lack of pressure for minimum core weights, to improve the swage accuracy. In the example, we would perhaps find the average core to be close to the mean between heaviest and lightest (but not necessarily so). If the average of ten cores was 46 grains, we would add the difference between lightest and average weights to this figure plus the buffer of an extra grain, to obtain a cut or cast weight of 48 grains (cut) or 47.5 grains (cast). Then, in swaging, we would set the core swage to extrude away all but the desired 46 grain core. This would result in various extrusion weights from a minimum of 1 grain for light cores to a maximum of 2 grains on the heaviest cores. To obtain a little better consistency, we might want to increase our buffer to 2 or 3 grains, at most, so that heavy cores bled
dangerous to the life of the die. It is too easy to force the lead too quickly through the small holes, creating tremendous pressures. Another problem with core swaging is the use of hard alloy lead in core moulds. If the lead is not close to pure lead, without antimony or bismuth added, it will flow poorly under safe pressures. Hard lead is usually easily acquired, and it remains a problem for the home swager to sort his lead so that only relatively soft, easily-swaged lead cores are cast. Various kinds of tests for lead alloy content are in use, and will be covered in later bulletins. Most of them rely on a method similar to the Rockwell hardness test, by pressing a ball into the lead and measuring the depth of penetration for a given pressure. There is yet another problem that can damage the core swage die, or the punch: dirt in the groove of the standard loading press can prevent correct alignment of the punch with the die. The punch will tip slightly and enter the die mouth, but will not be able to slip into a semi-floating alignment with the bore of the die because a grain of powder or accumulated dirt will hold the bottom of the punch button out from the correct position in the ram. Then, as the pressure is applied, the punch will be driven into the face of the die. The die is normally made of a tough tool steel, like Timken Graph-Air, and hardened to great strength and gall resistance. The punch is made of an oil-hardening carbon steel with less resistance to shear. Thus, the die will be saved while the punch acquires a severe tear about midway down its side. This raises a great amount of metal and prevents the punch from going into the die again. It must then be replaced. This can be avoided only by keeping the slot in the top of the press ram clean. A toothpick or other wooden tool is safe to use for scraping out this dirt, which can be primer residue, powder grains, or various kinds of shavings from both shell holders and brass cases. In the press designed only for bullet swaging, such as the Mity Mite press, there is no slot. Only a solid top with threads holds the die, which fits the ram, and the punch is held in a positive but multi-axial float by a special punch holder. The loading press is more critical about cleanliness because of the open construction and dependance on the ram slot tolerance for a degree of floating alignment. Dirt in the ram slot can also be the cause of damage to other punches, but the fit of the core swage punch to the die bore is one of the most critical, and the step of core swaging is the first one in making a box of bullets. Thus, it is usually the core swage punch which is ruined by being held out of alignment by a dirt collection in the ram slot. Presses, like guns, need cleaning to maintain proper tolerances and relationship with other equipment.
TECHNI CAL BU LL ET IN 8-12-76 Redrawing Bullet Jackets Determination of Internal Die Pressures
The same technique that is used for deheading fired .22 LR cases to make .224 jackets can also be used to draw larger calibers down to smaller diameter, longer jackets. This is a more simple procedure than deheading fired .22 rimfires, and allows the handloader to make any desired length of jacket (for heavier than normal bullets) out of the next larger calibers. For example, a .243 caliber .750" jacket which is commonly available can be drawn to anywhere up to an inch long . . . not available anywhere .. . in .224 caliber size. The procedure requires only a die and punch that are matched for the proper gap to reduce the jacket to size while thinning the walls to the desired amount for the extra length. Of course, with a given jacket there is only so much metal and as the jacket is made smaller it either gets longer or the walls get thicker. After a certain point is passed, the increase in length will start taking away from the original walls thickness, but there is a balance point at which the length and smaller diameter result in the same wall thickness. If, for example, an 8mm jacket is drawn to smaller, pre-war 8mm size, it will become longer by an amount determined by the gap between the punch and the sizing die. A small gap makes a longer jacket. It also increases the necessary force. But in each case the jacket will be somewhat longer than the original with a simple drawing set. This can be put to advantage, making jackets which permit open tip styles from jackets suitable only for soft points in a next-larger caliber. Open tip bullets normally require a longer jacket. A jacket reduced to the next smaller diameter in a drawing set will normally have just about the same weight, for the same type of bullet, as it had in the original size. A .750" long .243 jacket that makes a 60 grain 6mm bullet will also make a 60 grain .224 bullet in the same style. This is for modest increases in length. If the walls are thinned greatly, the ratio becomes more extended in favor of heavier bullets from the drawn-down jackets. A die set has been developed now that uses interchangable drop-in die rings and punches, so that the same 7/8 inch, 14 tpi holder and its hex-head top bushing can be used on any number of different size drawing sets, saving about half the cost of converting. The ring dies always face so that the wider part is down, toward the ram of the press. Jackets can be reduced only a few thousandths per draw, perhaps as much as 15 thousandths, if they are very thick walled, and up to 25 thousandths or 30 thousandths if moderate wall thickness. The entire diameter of the jacket end needs to be inside the guide portion of the ring die before any pressure is noticed. Draw-Die lube is used inside and outside, to increase punch life and reduc
The pressure inside a bullet swage die is far greater than many would think possible, because the area within the die is small and the leverage of a press great. The compound leverage type of press continually changes its leverage from perhaps a 10 to 1 mechanical advantage at the start of the stroke to as great as 100:1 for the last few fractions of an inch of travel near the top of the stroke. The power at any given point is the product of the force on the handle times the mechanical advantage. In theory, it becomes infinite as the links and pivots approach a straight line, although material yield points limit the actual stress produced. As an example of the pressures involved, assume a .224" core seating die with a bore size of .2238" and a punch that under pressure approaches that diameter are being used. A 160 lb. man can easily put 50 pounds of force on the press handle. At the start of the stroke, where the die is adjusted quite low in the press, the ratio of mechanical advantage might be only ten times the input. Thus, the ram would receive only about 500 pounds of force. The pressure inside the die, if the lead and jacket were brought up tight at this point within the die and against the punch end, could be only about 12,500 PSI . (Presssure is force divided by area. The area of a .2238" diameter punch is about 0.04 square inches). If the die were to be adjusted higher, so that the linkage of the press could nearly form a straight line before the punch contacted the lead core and compressed it, the mechanical advantage would be closer to 100:1. This would mean a pressure of about 125,000 PSI with a 50 lb. force on the press handle and a .2238" die. Of course, not even a rifle chamber usually is called upon to take this kind of extreme force and the die would swell or the punches would compress long before this pressure could be reached. The fact that a rifle chamber is usually over an inch in outside diameter, that it only has to withstand the force for a few milliseconds, the peak for only a fraction of that time, and the inertia of the chamber walls is great for a fast pulse-like application of pressure, all contrast to the pressure in a swage die. It can be sustained so long as the operator likes to press on the handle. The tiny die must hold not only in one piece, but must not swell even slightly, as the tolerances are measured in 100 millionths (0.0001 inches) for swaging dies. It may be appreciated that swage dies are made of a steel alloy that is heat treated and designed to much finer standards than most equipment on the reloading bench. However, if the die or other part of the system (the press ram top) should fail, it will usually not be the dramatic ending of a rifle blowing up. The energy in the pressure of a swage die is very small. In the hot gas of a rifle chamber, the pressure is the result of a great deal of stored energy. The gas of a rifle chamber can expand consider ably before the pressure is go ne... while the solid
of an inch to remove all the force, or reduce it to safe levels. This is one reason for failures which are blamed on every sort of material defect but the right one . . . material neglect, in application of far too much force for the job. The compound leverage press used for swaging is a far more potent tool than meets the eye.
The extreme of a light bullet is this .357 gas check with a core seated in it. It would be used m a stack of five to make multiple projectile loads. To make this short a bullet, the top punch needs to be held down into the die. This is done by adding a temporary half-inch diameter cylinder of steel on top of the normal punch within the die. The nose form is also snorter than normal, and in this case it is made to match the cup form of the base, to permit the bullets to stack upon each other. If this were to be a continual production bullet a special punch with a very long head should be ordered, with the matching dome to create the proper base shape and a similar reversed shape in the nose punch. This illustr ates one of the very versatil e features of swaging dies.
TECHNI CAL BU LL ETI N 9-25-76 Factors Determining the Diameter of Swaged Bullets
The precise diameter of a swaged bullet is usually controlled by factors other than the air-gauged or absolute diameter of the final point forming die. Some of these are under the control of the hand loader, and some are a matter of proper selection and matching of components or dies. One of the largest factors is the matching of the core seating die and point forming die. This can only be done to a modest extent in dies costing less than the price of about four man-hours of skilled labor, and is one of the reasons for the closer diameter control in higher priced dies. As an example of the amount of control involved, the .2240 diameter point forming die can be used. If the .2240 point forming die is air gauged and has an ogive length of at least half the total bullet (jacket) length with a radius of at least four calibers, or .896 inches, then the finished bullet diameter will be smaller than the precise die cavity size by the amount of elasticity or spring-back in the jacket material, the thickness and viscosity under pressure of the lubricant, and the surface smoothness of the die. It will be made larger by the amount of pressure necessary to form the point to the desired fineness or diameter of tip, which increases as the surface smoothness decreases. The pressure also increases, thus tending to increase the diameter toward the absolute size of the die cavity, as the jacket thickness and resistance to cold flowing increases. It is possible to make a bullet in a die,finding it has smoothness less than desirable and thus ejects moderately hard, and then lap the die further (which would enlarge the cavity) . . . only to find that even with a slightly larger cavity, the additional smoothness requires less pressure to form the same tip size, and thus a smaller bullet results from this larger die cavity! With all other factors the same, dies with smoother surfaces produce smaller bullet for a given air-gauged cavity size. The control that matching a core seating die to a given point forming die produces is even greater than these effects, however. If the same point forming die is used with two different core seating dies, it will normally produce a smaller finished bullet (by as much as a half-thousandth of an inch) from a smaller seated core and jacket. Thus a .2240 point forming die used with a .2230 core seating die might make .2235 diameter bullets at the same pressure and tip size, to all outside appearances, as are present when the same die is used to make a .2238 inch diameter bullets with a .2235 inch core seating die. Of course, the air-gauged cavity of the core seating die will be likely to be as much as three or four ten-thousandths (300 to
jacket. One point forming die can be used to make a number of different diameters, by using various core seating die diameters. This explains why the core seating die must be matched to the point forming die when precise changes or specifications of final bullet diameter are necessary. A point forming die cannot simply be "lapped" to make a precise bullet without matching to a specific core seating die, lube and jacket.
The .50 caliber machine gun bullet is made from a jacket that is already formed into final shape, with the exception of the base. This kind of full-jacket bullet in most calibers is expensive to swage because of the number of extra jacket f orming dies and special punches. It offers little or no improvemnet in performance over standard styles, and it generally not as accurate as the closed-base type. Handloaders are best advised to avoid t his kind of bullet in their home swaging, though of course if really desired, the extra parts and dies can be
T E C H N I C A L B U L L E T I N 1 0-1 5-76 Removal of Stuck Bullets in Point Forming Dies The removal of a stuck bullet in a point forming die can normally be accomplished by forcing a film of lubricant to compress the jacket while at the same time reforming the bullet tip to afford a better surface for the ejection pin to work upon. This can be done in many cases by simply removing the die from its holder, making sure the ejection pin is not stuck in the die (if it is, then it must be twisted and pulled out before further work is done), and reassembling the die. A short lead core, about a third to a half the length of a normal core for the bullet in the die, is dipped completely in a good lubricant. This short core is then placed in the mouth of the die, and gentle pressure applied with the die in the press. The effect is to force the surplus lube along the sides of the stuck bullet, acting as a wedge that compresses the jacket inward and reapplies a film of lubricant between the jacket and the die wall. In quality bullet swage dies, a graphitic tool steel with micro-pockets of free graphite will absorb the lubricant and retain it under extreme pressure. A typical die steel is the very fine Timken Graph-Air, one of the three steels in the family containing Graph-Mo, Graph-Air, and Graph-Tung. All three steels are somewhat costly, and make good dies, but the Graph-Air has the finest stability of dimension with heat treatment and is air-hardening (no brine or oil quench is used, which greatly relieves the internal stress of quenching). When the pressure is released the lubricant film can be retained and the pockets of graphite inclusions act as suppliers of lubricant during the ejection of the bullet in the normal manner. If this process fails, it is possible that a vastly oversized jacket or seated core was used. In the point forming die, anything larger than the air-gauged bore size is vastly oversized. With jacket material, the amount of compression force needed to reduce the jacket below that size created from tight contact with the die walls depends both on the jac ket thickness and anneal, and on the amount of prior compression. When the jacket was stretched to bore diameter or beyond before insertion, rather than being expanded upward by pressure to meet the die bore, this force is enormous and cannot be supplied by the hydraulic wedge effect alone. Removal of the bullet then requires mechanical means, such as precision boring and threading into the jacket walls, and installation of a tap to act as a handle for external pulling force. This is best accomplished in a precision lathe of the finest quality, not by hand, since penetration of the jacket wall can ruin the die. Such work is best referred to the factory. In no instance is it wise to attempt to drill the bullet from the die with an ordinary drill press or hand tools. Even with a good lathe at hand, the depth of the hole st be calculated carefully so as not t
reach the ogive. However, there is a possibility of removing a stuck bullet by removing the die from its holder, cutting a piece of tempered spring wire as long as the die, and of the correct diameter to fit the ejection pin hole, and simply driving it into the bullet. Commonly the wire will penetrate the bullet and emerge from the base. If it is centered, a small fast-rate tap can sometimes be threaded into the hole and used to pull out the bullet. However, such work is very risky unless absolute care is taken not to penetrate the jacket walls and score the die. It is never wise to melt the lead from a stuck bullet, as the jacket by itself is even harder to remove than the filled bullet, and the heat will spoil the temper and hardness of the tool steel die, which must then be re-heated to form the carbides and air-quenched.
A few of the dozens of possible multiple jacket combinations used to make bullets penetrate deeply before expansion, or to prevent expansion completely. Telescoping, inver ting jackets within each other, using gas checks, primer cups, two or more cores separated by jackets or non-expanding material, even smaller caliber bullets swaged into the jacket of larger cali bers, with or without additional core lead, are all examples shown here.
T E C H N I C A L B U L L E T I N 11 -1 -76 Dealer's Guide to Customer Questions About Bullet Swaging Bullet Swaging is almost a dark science in the minds of many shooters, simply because of lack of information. Since there has been no successful, long-term attempt prior to this time to develop the equipment, complete product lines, and the information where it could be profitably handled at the dealer level, most dealers know very little about swaging and cannot advise their customers about it. While hardly a comprehensive guide, this bulletin does attempt to give the most common questions, exactly as they are asked in thousands of letters to the manufacturer, along with brief and generalized answers that apply most of the time to the customer's situation. These same questions and answers may also help advanced bullet swagers both explain their activities to other shooters and perhaps clear up some problems for beginners. Q.WHY IS SWAGING ANY BE TTE R THAN CASTING? A. Swaging is not necessarily "better" but it' offers greater versatility and the entire spectrum of performance, from low velocity expansion to high velocity penetration, at a lower cost per the total equipment investment and less time spent at the bench. In some cases a swaged, jacketed bullet is the only kind that will perform properly, and in others the cast bullet is better for the purpose because it affords a lower cost per bullet. A full discussion is available by ordering TB 6-10-76, a 4-page summary of Casting and Swaging methods. Q.
IS A SPECIAL PRESS NECESSAR Y FOR SWAGING?
A. Any of the modern, stout reloading presses will handle handgun bullets and small caliber rifle bullets such as the .224 and the 6mm caliber. Larger calibers require a special press to avoid damage to the slotted ram. The frames and pins are strong enough in any press of modern design, but the compound leverage presses are equal to the task while making the operator effort much less. The weak link in any loading press is the slotted ram, which can fold under the high pressures of big caliber rifle bullet swaging. For long, larger caliber bullets a threaded, solid top ram is required such as the Mity Mite or other special swaging press. These also feature a shorter ram stroke and greater power (which means less effort is needed).
Q.
WHERE
CAN
I
GET
COMPONENTS,
LIKE
LEAD
AND
JACKETS?
A. Corbin does handle all the components, and ships lead wire in 25 lb. spools of the proper diameter prepaid, and jackets in lots of as little as 100 (a thousand is a better buy for a customer, and a stock of from 5,000 to 25,000 is not excessive for a dealer in the popular calibers). Lead wire is available from National Lead, RSR Corporation, and many other smelter outlets. Usually a minimum purchase of from $200 or 500 lbs. is asked from larger lead suppliers, which is the only major advantage of buying from Corbin (we do know the proper sizes, etc., for swaging, of course but will advise anyone regardless of where he buys the lead). However, greater economy at a slight increase in time is achieved by using 4-cavity, bench-mounted core moulds. Any soft lead supply then takes care of the cure situation. Lead wire is much faster to use on a moment's notice, by simply purchasing (or making) a decent core cutter that will not bend the lead wire or smear it. Corbin has these items in stock. Q. WHAT IS TH E TOTA L COST OF GE TT ING INTO SWAG ING ? A. A customer wants to know, really, how much of the rest of the iceberg he isn't seeing! In truth, he probably remembers casting; first a mould, then a good pot,finally an electric thermostatic control pot, commercial dippers, a lubricator and sizer, then a whole raft of moulds for each weight and style of bullet, different lubricants, etc. He also remembers that the first cast bullet, shot perhaps unlubed and unsized, was fast to make . . . but later, to avoid leading and get the desired quality a lot of handling and secondary operations added to the time involved.
This is a big factor in preventing a potential customer from trying swaging. He does not know that one set of dies make a vast number of bullet weights and styles in the handgun type, just by changing punches. Nor does he know that the number of necessary accessories for good results are much fewer than with casting. The main tools are simply the dies themselves. An experimenter will want extra punches for his handgun die sets to make lots of different bullet shapes, which are available at just about the price of a lead dipper. Since he already owns a loading press, he has no other cost in tools if he swages handgun or smaller rifle calibers (not over 6mm). If he wants to go first class, he can purchase a special swaging press with the self-aligning punch holder and custom dies. Bullets that come out of the die are ready to shoot, with no further handling.
The only additional accessories of consequence might be a cannelure tool, which is not a necessity except with some tubular magazine rifles and for better accuracy in the autoloading pistols (a positive case band to seat the bullet against . . . nothing to do with swaging in any case except the same tool is used). In rifle bullet making, a major accessory is the core swage die (included| in the top of the line kits and set of custom dies) which makes the raw cut lead or cast lead core closer to weight and dimension before it is put into the jacket and swaged to place. A "power ejector" or mechanical leverage type of device for getting the bullets back out of the dies is very nice as an accessory, but a mallet works as well for most shooters. The ejector unit reduces wear and shock on the die and punch set, forms nicer bullet tips, and makes the process even faster and more pleasant. But it is not required. In general, any caliber can be "gotten into" at a minimum of about $75 for the total original purchases including some jackets and accessories that are desirable. The top of the line equipment including every possible accessory of benefit might cost close to $200, which also includes a special press. Again, refer to TB 6-10-76 for more detailed comparison with casting. The cost is very favorable. Q. CAN I MAKE MA KE MORE THAN ONE CA LIB ER WITH A SET OF SWAGE DIES?
A. Each die or set of dies makes one caliber of bullet. The diameter is controlled by the tool steel die itself, which holds the tremendous pressures necessary to compress the bullet material into precision conformity with the die walls. Each die set, then, makes one diameter of bullet with only slight change possible (meaning a few ten thousandths of an inch depending on technique and lube). However, many forms and weights in each caliber may be possible, depending on the particular set: of dies. A .355 die will make .380 and 9mm bullets, of course, while a .357 die will make .38 Special, .357 Mag., etc. Q. CAN
I MAK E BU LL ET S AS GOOD AS THE FACTORY
BULLETS?
A. A handloader can make bullets as good as the best factory bullets with care and practice in the same style as the factory, but he can also make more kinds and weights of bullets than any factory offers in his favorite caliber. Whether they are as good or not depends on his use of them and his own ideas about bullet design. Perhaps his weight control and dimension control are superior the the factory bullets he usually buys, but his design is completely
box of hand-made swaged .224 rifle bullets using long jackets redrawn from 6mm .750" jackets (a simple operation at home), but used in a 1-1 2 twist rifle and weighing 80 grains! Are they better than factory bullets? Could they be is used correctly? Those are better answered individually! The main point is that home-swaged bullets can indeed be as high in quality and control as factory swaged bullets. Without but rare exception every factory bullet is swaged in a similar method but using more dies. Home dies can be as good, but usually have to be better, in finish and fit in order to work at all ! But it is not in order to make better bullets, or to make cheaper bullets, but simply to make the kind of bullets the moment requires that swaging exceeds the potential of simply buying factory bullets.The swager normally is a heavy component buyer and will continue to be so, even in the same caliber, because he continually compares and tests, experiments and modifies. Q. ISN'T SWAGING HARD ON MY REL OADI NG PRE SS? A. It will be, if good judgement isn't exercised, but then so will reloading. In potential damages to the press there are snapped frames and bent "li ps" at the top of the slotted ram. These things happen only when the swager attempts to force things beyond any reason, giving brute power to a situation calling for intelligent work. Never, in normal swaging operations with .224 or 6mm rifle calibers, or with handgun calibers using the short, fat bullets associated with revolvers and autoloaders, have any properly operated swage dies and punches been used to wreck a press in our knowledge. This is only done through ignorance.
The pressure involved in swaging is very high, but it gets this way because of the small area and closed volume within the die, not because of vast forces on the press or handle. If a press will resize a .30-06 case in a regular full-length sizer, it will swage any bullet for the press stress is the same, or less, with swaging in the small rifle and all handgun calibers. The main problem is the screw-stock (soft low-carbon steel) ram used almost universally in reloading presses, which will collapse slightly where the thin lip is left atop the shell holder slot. This can occur in any press if used hard, but is noticed more with swaging because of occassional abuse. It is a common idea among writers and handloaders that swaging absolutely requires pressures and forces that can only be achieved by behemoths on the press handle. The operation does not require great effort on the h and le. .. it makes high pressure because of the very small area to which normal effort is applied. With a compound
two-or-three-finger force will do the job on almost any caliber. This generates tremendous pressure, but not on the handle, or against the frame, any more than a high pressure rifle needs to have a six-foot cheater bar on the trigger to fire it! The pressure comes from other factors in both cases.
jacketed bullet is the best all around bullet because it can do so much both in velocity range and in changes in performance by changes in design, but it is by no means the only kind of bullet that is swaged today. Q.
Q. I H AVE A Lyman Ail-American Turret, A Bonanza Co-Ax, an RCBS Jr., or ANOTHER PRESS WITH SPECIAL FEATURES, M O DE S T L E V E R A G E , O R U N U S U A L D E S I G N . C AN I U S E I T FOR SWAGING? A. Better not. The reason is that the "standard" press design both in slot dimensions and in leverage, clearance for punches and accessory items, stroke, etc., is the line represented by the CH Champion, the RCBS Rockchucker, the Pacific Multi-Power, and similar presses of about the same basic construction and design. If a person has a CH Swage-O-Matic, A Herter 9-Ton, or a Mity-Mite then he is equipped with the most nearly ideal system for the kind of dies that go with these special presses. If he has a standard, heavy-duty type press for reloading, he is best equipped for the regular 7/8 X 14T dies that use slotted rams for the bottom punch. But the simple leverage presses, the turrets, and the other fine presses mentioned have features best suited for being set up and used as reloading presses, as they were intended, and perhaps not so well suited for use with the tools of swaging. This does NOT mean they are weak, undersirable, or otherwise not "up to par" . . . quite the contrary. A special press is worth more when kept for its prime purpose, and the swager is better off with a separate press just for swaging and heavy case forming operations. A bullet swager is really "i nt o" handloading to the point where he ought to have a top of the line press from one of the major firms in addition to his special reloading equipment. As a dealer, it is a real favor to the handloader to try and get him to see the benefit of obtaining at least one compound leverage, single-station conventional press if he is going into swaging. It makes the whole operation of reloading one's own bullets faster and easier if two presses are available and don't have to be continually changed in their tooling to try the bullet in a handload. Q. CAN JUST LEAD B UL LE TS BE SWAGED, WITHOUT A JACKET, TO SAVE MONEY? A. Sure, and they can work pretty well in small automatics, in muzzle loaders, in target handgun loads. . . even with a rather minimal amount of lube, placed by using a rolled cannelure just like the factory rounds, lower velocity loads work fine in most cases. The
HOW CAN SWAGIN G EQU IPMEN T BE ACC UR ATE IF IT COST L E S S THAN T H E B E N C H R E S T G E A R P R I C E S OF $300 to $500 OR MORE? A. Volume. That's the whole thing in a nutshell. Electronic control, electro-chemical die laps, hundred and thousand part runs, all these depend on having a price that in turn makes such volume possible. It does not mean a die is not precise or made of high grade material if it costs a tenth of the price of a single order, hand-made custom die. The time involved in making one die by hand to customer orders includes the cost of small orders in steel, in stepped up costs for portion of machines and tools amortized, much set-up and re-tooling time, and all the other costs of small volume work done by dedicated hobbiests or people doing other work for their main income. Until now, it was the only way to get good swaging equipment. Swaging equipment will probably never be "mass produced" because of the tremendous amount of hand fitting and testing required. But at least it can be sold in reasonable volumes to eliminate the one and two die per week delivery problem that means high prices. A closer approach to extreme dimension control is achieved by more hand work, which is available only at the cost of longer delivery delays, such as the custom Mity Mite system as compared to the catalog dies. The price is only about double, but the catalog dies can be stocked while the MM dies take 30 to 60 days for delivery.
A half- inch long .357 jacket makes ideal high velocity, conical type bullets but also can make heavy, moderate speed semi-wadcutters, as shown. This jacket is reall y made for the 'Super- Vel" style of bullet but can be used in a single die if a bullet of at least 160 grains is acceptable.
T E C H N I C A L B U L L E T I N 12 -1 -76 Bullet Designs for Deep Penetration: Multi-Jacket Swaging Swaged bullets with their pure lead cores make excellent expanding bullets for use in defense and against small game, but the use of the swaging technique also permits special, deep penetrating designs for both handgun and rifle bullets. Larger game requires a deep penetrating bullet with a portion of the weight being retained in a non-expanding form. Such bullets can be made by the use of partitions and multiple jackets. The home swager can use smaller caliber jackets, seating lead cores in them as would be normally done to make the smaller caliber bullet, but then inserting these seated cores as the bottom half of the larger caliber bullet. It is only necessary to find two jackets that will telescope within each other, and generally the smaller one must be about half the length of the larger caliber. The smaller seated core and jacket is inserted with the base toward the mouth of the larger jacket. Another lead core is placed over this assembly and swaged into place, just as with seating a normal full-length core, and the bullet is formed in the normal manner thereafter. Combinations of jackets that will generally telescope within each other would include the 6mm jacket into a .30 caliber jacket, the .41 Magnum jacket into the .45 ACP, and the .38 into the .44. Full jacket handgun bullets can be made by putting a proper length core between a pair of half-jackets or a half jacket and a three-quarter jacket of the same caliber. The jacket must be formed into a nose shape without excessive sharpness to the edges or the jacket bottom will tear as it forms. Wadcutters are excellent for this style of bullet. The use of a partition between two cores, to that the bottom core will be protected against rapid expansion, can be accomplished with nothing more than a fired primer. The anvil can be pried out, leaving a cup that will slip into the jacket on top of a pre-seated short core. If the flanges of the cup are inserted toward the mouth, the cup will generally expand to fill the jacket completely if it is undersized. This creates a wall between two cores, after the top core is firmly seated and the point formed. The only serious restriction is that the cup should be below the ogive in order to keep the bullet from sticking during the point forming operation. Examples of partition materials would be the small rifle primer cup in a .224 jacket, the large rifle cup in a 6mm, a shotgun primer cup in a .30 caliber jacket, and similar slip fits with gas checks in the larger jackets In the .38 caliber pistol jacket, a .30 caliber gas check
effectively protected by swaging a gas check over it, provided that not too deep a draw results. Gas checks give some point protection but in general they are thin enoughto deform more than an inverted jacket upon striking any substantial target material.
The explosive power of a hollow point, butt on nose semi-wadcutter (made in one die with two punches in succession) is both good and bad, depending on applicati on. It is excellent for poli ce use, since it is a quick man-stopper. For home defense, the soft lead bullet tip will quickly bring the bullet t o a stop in passing through walls and doors, reducing danger from shot which miss their mark to neighbors. For big game this bullet is a mistake, as it usually fails to penetrate to vital organs on tough animals, or even on deer if quartering away from the shooter so that deep penetration is needed. A protect ed point or tightly-closed conical would penetrate better.
